Radial-piston multiple-action hydraulic motor

ABSTRACT

A radial-piston, multiple-action hydraulic motor comprises a casing in which a rotor with an even number of rows of radially arranged pistons is rotatable, the casing having guides with profiles containing noncontrolled and controlled sections. The pistons of one half of the rows interact first with the noncontrolled sections then with the controlled sections and the pistons of the second half of the rows interact first with the controlled sections and then with the non-controlled sections of the profiles. A journal-type distributor is installed in the rotor and has at least two coaxial journals with channels for distributing working fluid and controlling the displacement volume of the hydraulic motor by turning synchronously in opposite directions relative to their axis, the distributing channels of each journal communicating hydraulically with one half of the rows of the pistons.

a United States atent [151 3,66 1,057 Rogov May 9, 1972 [54]RADIAL-PISTON MULTIPLE-ACTION FOREIGN PATENTS 0R APPLICATIONS HYDRAULICMOTOR 152,695 10/1920 Great Britain ..91/492 [72] Inventor: AnatolyYakovlevich Rog v, Mo k k i 152,264 l/l952 Australia 91/498 obl., pos.VUGl, 24, kv. 26, Ljubertsy, U.S.S.R. Primary Examiner-Paul E. MaslouskyFiled: y 1970 AtIorrieyW2iters, Roditi, Schwartz & Nissen [21] Appl.No.: 37,394 [57] ABSTRACT Related Us. Application Data A radian-piston,multipleiction hydraulic motor comprises s v casing in which a rotorwith an even number of rows of radi- Commuatlon 0f 738-357, June 19,1968, ally arranged pistons is rotatable. the casing having guidesabandoned with profiles containing noncontrolled and controlledsections. The pistons of one half ofthc rows interact first with the[52] Cl 91/492 91/498 noncontrolled sections then with the controlledsections and [51] Cl "Folb Folb l3/06 the pistons of the second halfofthe rows interact first with the [58] new of Search 498; controlledsections and then with the non-controlled sections 103/161 of theprofiles. A journal-type distributor is installed in the 56 R f Ct drotor and has at least two coaxial journals with channels for l 1 eerences I e distributing working fluid and controlling the displacementUNITED STATES PATENTS volume of the hydraulic motor hy turningsynchronously in opposite directions relative to their axis, thedistributing chan- 456,315 7/1891 Ruths ..91/482 neis f each journalcommunicating hydraulically with one 1,302,709 5/1919 Ragot ..91/492 hlf fth rows f h pistorm 2,099,630 11/1937 Schneider ..91/498 2,303,68512/1942 Eden et a1 ..91/498 3 Claims, 6 Drawing Figures PATENTEDHAY 9I972 3,661,057

SHLEI 1 [IF 2 Ill 11/ F F L 20 L, FIG. I

RADIAL-PISTON MULTIPLE-ACTION HYDRAULIC MOTOR This application is acontinuation of application, Ser. No. 738,357, filed June 19, 1968, nowabandoned, and relates to radial-piston hydraulic motors.

Known in the art is a multiple-action hydraulic motor with radialpistons interacting on one side with guides, accommodated in the casingthereof, the profiles of each of said guides having noncontrolled andcontrolled sections and on the other side with a journal-type workingfluid distributor installed so that it can be turned for controlling thedisplacement volume of the hydraulic motor.

A disadvantage of the known hydraulic motor is that it cannot ensurecomplete uniformity of the torque and speed of rotation, in the courseof control.

An object of the present invention resides in eliminating the aforesaiddisadvantage.

Another object of the invention resides in providing a hydraulic motorensuring a complete uniformity of the torque and speed of rotation inthe course of controlling its displacement volume.

This object is achieved by providing a radial-piston multiple-actionhydraulic motor with an even number of piston rows, said pistonsinteracting on one side with the guides accommodated in the casing, theprofiles of each of said guides having noncontrolled and controlledsections and on the other side with a journal-type working fluiddistributor installed so that it can be turned for controlling thedisplacement volume of the hydraulic motor. According to the invention,the journal-type fluid distributor consists of at least two coaxialjournals turning, synchronously during volume control operation, inopposite directions about a common axis. The distributing channels ofeach journal communicate hydraulically with one half of the piston rows.The guides are made in such a manner that the half of the piston rowsinteract first with the noncontrolled sections of the profile, then withthe controlled sections. Conversely, the other half of the piston rowsinteract first with the controlled sections and then with thenoncontrolled sections of the profile.

Synchronous turning of the journals is ensured by toothed quadrantssecured to the journals and meshing with counteropposed racks performinga reciprocating motion.

Given below is a detailed description of an embodiment of this inventionwith reference to the accompanying drawings in which:

FIG. I is a sectional view of the radial-piston hydraulic motoraccording to the invention;

FIG. 2 is a view along arrow A in FIG, 1, the structure visible in FIG.2 not being shown in FIG. 1;

FIG. 3 is a section taken along the line IIIIII of FIG. 1;

FIG. 4 is a section taken along the line IV-IV of FIG. 1;

FIG. 5 shows a torque diagram for one half of the piston rows; and

FIG. 6 is a torque diagram for the other half of the piston rows.

Installed in the hydraulic motor casing 1 (FIG. 1) which is closed atthe ends with covers 2 and 3 is a rotor 6 rotating in bearings 4 and 5.

The rotor 6 has an even number of rows of cylinders 7. The cylinders 7with pistons 8 are installed in each row radially. The pistons 8 areconnected to pivots 9 carrying rollers 10. Said rollers interact withguides 11 accommodated in the casing 1.

Located in an axial recess of the rotor 6 is a journal-type workingfluid distributor consisting of two coaxial journals 12 and 13. Eachjournal is in hydraulic communication with one half of the piston rows.For this purpose the journals l2 and 13 have, respectively, channels 14and 15 and ports 16 and 17 through which the working fluid flows underthe pistons 8 after which it is forced out through channels 18 and 19and ports 20 and 21 into the return line.

Synchronous turning of the distributor journals l2 and 13 is ensured bytoothed quadrants 22 (FIG. 2) and 23, installed on each journal andmeshing with counter-opposed racks 24 which are connected to the piston25 of a hydraulic cylinder 26; when in the initial position, thequadrants 22 and 23 are located at from each other and the angle ofturning B of said quadrants from the initial position in this case isequal to zero.

The working fluid is fed into, and discharged from the hydraulic motorthrough a header 27 (FIG. I) which has circular channels 28 and 29communicating, respectively, with the channels 14, 15 and l8, 19 of thejournals l2 and 13.

The guides 11 have a periodically repeated profile which governs thenature of movement and the number of piston cycles per revolution of therotor.

Within each cycle, corresponding to the rotor angle of a=2 rr/x (where xis a number of cycles per revolution) (FIGS 3,4), the roller 10 rollsover four sections 30,3l,32,33 of the profile of the guide 11.

While the rollers 10 move over the sections 30 and 31, highpressurefluid enters under the pistons 8 connected to said rollers and the rotorturns through angle a,

As the rollers 10 move over the sections 32 and 33, the pistons 8 slidetowards the center of the rotor 6, forcing the fluid out into the returnline and the rotor turns through angle a The sections 30 and 32 arenoncontrolled ones and the profile of each of said sections is aparabolic curve; as the rollers move over this curve the rotor turnsthrough angle 01 the sections 31 and 33 are controlled sections wherethe supply of the working fluid is controlled; the profile of each ofthese sections follows an Archimedes spiral; while the rollers 10 rollover this curve, the rotor turns through angle 01,.

The noncontrolled sections 30 and 32 and controlled sections 31 and 33are so located on the guides 11 which interact with the rollers 10connected to the pistons of one half of the rows of the cylinders 7 thatthe rollers 10 first interact with the noncontrolled sections 30 and 32(FIG. 3) and then with the controlled sections 31 and 33. The rollers 10connected to the pistons 8 of the other half of the rows of thecylinders 7 interact first with the controlled sections 31 and 33 (FIG.4) then with the noncontrolled sections 30 and 32.

The hydraulic motor operates as follows.

The working fluid flows under a high pressure through the circularchannel 34 of the header 27 into the channel 14 and port 16 of thejournal 12 and into the channel 15 and port 17 of the journal 13 andthence under the pistons 8. The pistons 8 transmit the effort producedby the fluid to the pivot 9 and rollers l0 and the latter interact withthe profiled sections of the guides 11. The lateral forces originatedduring this interaction turn the rotor 6. The pistons 8 perform aworking stroke, moving from the lowermost to the uppermost position onthe sections 30,31. As the rollers move over to the sections 32,33, thefluid is forced from under the pistons 8 connected to these rollersthrough the channels 18 and 19 and the ports 20 and 21 of the journals12 and 13 into the circular channel 35 of the header 27 and thence intothe return line.

When the quadrants 22 and 23 connected to the journals l2 and 13 are inthe initial position, that is, at 180 to each other and their turningangle [3 is equal to zero, the displacement volume of the hydraulicmotor is a maximum. In this position there are no fluctuations of themotor torque and speed. When the quadrants are offset by an angle lessthan 180, the motor torque and speed is regulated due to reduced strokeof the pistons caused by offset timed relation between the supply andoutlet channels and the pistons.

As the journals [2 and 13 are turned synchronously through angle at a /3O by the rack 24 and toothed quadrants 22 and 23, the working fluidenters under the pistons 8 and the rotor turns through angle (l -B. Thisreduces the working stroke performed by the pistons 8 under the force ofthe high-pressure working fluid and this results in a reduction in thedisplacement volume of the hydraulic motor.

In such a method of controlling the displacement volume of the hydraulicmotor, the changes in the torque M in accordance with the turning anglea of the rotor 6 follow the diagram given in FIG. 5 for one half of therows of pistons and in FIG. 6 for the other half of the rows of pistons.These diagrams are piecewise linear functions with the sectioninclination angle of different direction but of the same magnitude. Asthe hydraulic motor torque is a result of summation of the momentsproduced by both halves of the piston rows, the summary torque does notfluctuate which can be proved by superposing the diagrams given in FIGS.and 6.

For reversing the hydraulic motor, it is necessary to change thedirection of flow of the working fluid fed under the hydraulic motorpistons. in this case the high-pressure fluid enters under the pistons 8through the circular channel 35 of the header 27, the channels 18 and 19and ports 20 and 21 in the journals l2 and 13 and is discharged fromunder the pistons through the channels 14 and 15 and ports 16 and 17 ofsaid journals into the circular channel 34 of the header 27 and thenceinto the return line.

The description has disclosed a hydraulic motor with a rotating rotor.However, the hydraulic motor may be made with a rotating casing and astationary cylinder block.

I claim:

1. A radial-piston multiple-action hydraulic motor comprising: a casing;a rotor with an even number of rows of radially arranged pistonsinstalled in cylinders provided in said casing; guides in said casingeach having profiles with noncontrolled and controlled sections, thepistons of one half of the rows interacting first with the noncontrolledsections then with the controlled sections and the pistons of the secondhalf of the rows interacting first with the controlled sections and thenwith the noncontrolled sections of the profile; a journal-typedistributor installed in said rotor and comprising at least two coaxialjournals having channels for distributing working fluid to saidcylinders, said distributing channels of each journal communicatinghydraulically with the cylinders of one half of the rows of said pistonsand means coupled to said journals to turn the same synchronously inopposite directions and alter the time of fluid feed into said cylindersrelative to the position of said pistons relative to said guides,whereby to control the stroke of said pistons for controlling thedisplacement volume of the hydraulic motor by turning of the journalssynchronously in opposite directions relative to their axis.

2. A motor as claimed in claim 1, wherein said means to turn thejournals synchronously comprises toothed quadrants secured to saidjournals, and counteropposed racks meshing with said journals andreciprocably displaceable to oscillate the racks and the journals towhich they are secured.

3. A motor as claimed in claim 1, wherein said noncontrolled sectionsare of parabolic shape and said controlled sections are of spiral shape.

exist

1. A radial-piston multiple-action hydraulic motor comprising: a casing;a rotor with an even number of rows of radially arranged pistonsinstalled in cylinders provided in said casing; guides in said casingeach having profiles with noncontrolled and controlled sections, thepistons of one half of the rows interacting first with the noncontrolledsections then with the controlled sections and the pistons of the secondhalf of the rows interacting first with the controlled sections and thenwith the noncontrolled sections of the profile; a journal-typedistributor installed in said rotor and comprising at least two coaxialjournals having channels for distributing working fluid to saidcylinders, said distributing channels of each journal communicatinghydraulically with the cylinders of one half of the rows of said pistonsand means coupled to said journals to turn the same synchronously inopposite directions and alter the time of fluid feed into said cylindersrelative to the position oF said pistons relative to said guides,whereby to control the stroke of said pistons for controlling thedisplacement volume of the hydraulic motor by turning of the journalssynchronously in opposite directions relative to their axis.
 2. A motoras claimed in claim 1, wherein said means to turn the journalssynchronously comprises toothed quadrants secured to said journals, andcounteropposed racks meshing with said journals and reciprocablydisplaceable to oscillate the racks and the journals to which they aresecured.
 3. A motor as claimed in claim 1, wherein said noncontrolledsections are of parabolic shape and said controlled sections are ofspiral shape.